1. Field of the Invention
The present invention relates generally to a computer system for wirelessly connecting peripheral devices and more particularly to methods for wirelessly connecting a host computer to supporting WiFi peripherals and for wirelessly supporting additional display systems.
2. Description of the Background Art
In recent years, there has been growing popularity for the WiFi standard for wireless communication. WiFi is a collection of standards of which the main standards are 802.11g (which incorporates 802.11b) and 802.11a. Within the WiFi standard there are numerous required and optional modes as well as a continually advancing set of enhancements and proposed enhancements. WiFi can be found in practically every new portable computer and in an increasing number of desktop computers, telephones, televisions, digital media players and cellular phones. WiFi based Local Area Networks (WLANs) are found in most airports, coffee shops, businesses, college campuses, city centers and an increasing number of other areas.
Developing effective methods for operating wireless electronic peripherals is a significant challenge for modern system designers. In a typical system, wireless peripherals, such as a keyboard and mouse, use dedicated RF chips with their own RF channels to communicate with a computer. This adds cost to the computer system and if, as is typical, the computer does not integrate the RF chips for peripheral devices, requires the use of an external dongle.
Recently, computers and cell phones have utilized the Bluetooth standard for supporting a variety of peripherals including keyboards, mice and telephone headsets. Bluetooth is a more general standard that is more readily integrated directly into computers and cell phones. However, Bluetooth still adds a dedicated RF subsystem and since Bluetooth uses the same RF spectrum as WiFi's 802.11g, additional care must be taken to avoid interference between the two. Other power or cost sensitive devices, such as the Sony Play Station Portable (PSP) may include only a WiFi RF subsystem and the most convenient method for adding wireless peripherals is to provide wireless peripherals supporting WiFi.
A device such as a computer on a WiFi network has two modes of operation, Infrastructure mode and Ad-Hoc mode. Infrastructure mode allows the computer to communicate with the Access Points (AP) of a WiFi network and gain access to services such as Internet. Ad-Hoc mode allows devices to talk directly to each other without utilizing the APs. These modes are mutually exclusive so a device can not talk to both an AP and another device during the same session.
Mesh Networking is a technique for wireless communications where, instead of a conventional hub-and-spoke model with every device connecting to a central access point, every device (area) acts as a repeater or router. When mesh-enabled devices are in range of one another they automatically create a wireless mesh network, and traffic hops from device to device until it reaches the nearest AP that includes wired backhaul. Mesh networking reduces the need for more powerful central AP antennas and improves wireless coverage. One downside of mesh networking is that it increases the minimum processing capability needed by each mesh device. While add mesh capability typically would not be a problem for a computer, adding conventional mesh capability for peripherals and in particular for low cost battery based peripherals is a large burden.
For high bandwidth and time critical communication, such as between a computer and a computer display, it may be particularly desirable to add RF capacity beyond the RF channel used for WiFi infrastructure. If the more general network traffic is not normally part of the same RF channel then such a channel can operate in a high QoS mode. Options for the additional RF channel may include an additional channel of WiFi (WiFi supports multiple non-overlapping channels), a WiFi channel in a different RF band (802.11a operates in the 5 GHz spectrum while 802.11g operates in the 2.4 GHz spectrum) or a different RF protocol such as Ultra Wide Band (UWB).
Adding additional RF channels to the host system is best done for peripheral devices that need high bandwidth and high QoS. For low bandwidth low cost peripherals it is not desirable to either add additional RF channels or increase the complexity of the WiFi features. However, standard WiFi does not support a host system that can concurrently operate a single WiFi channel for both infrastructure mode and peripheral support. Therefore, what is needed is an effective Wireless architecture where a host system can maintain the best available mode of access to the WiFi AP infrastructure while concurrently utilizing low cost peripherals which also use the WiFi RF channel where any additional RF channels added to the system are used for high performance connections.